because of weather....despite his campaign manager saying just yesterday that he would give the speech "rain or shine"
"If you’re counting, that’s a decrease in capacity of 73% from Bank of America Stadium. At least every seat will (should) be filled now."
http://www.redstate.com/2012/09/05/2...smaller-venue/
http://www.foxnews.com/politics/2012...ther-concerns/
Some people thinking he can't fill the seats